Right now as Duke and Banker, I am able to see the food in the duchy and realm, which is great!
I cannot create any offers for the city though. I have a different lord who is outside the realm and can understand why he cannot set up offers, but within the realm while not traveling should work, no?
EDIT:
Never mind. I am an idiot. Didn't realize I could scroll down on the marketplace page.
So far so good!